Direction and speed of actin filaments moving along thick filaments isolated from molluscan smooth muscle.
The active movement of fluorescence-labeled actin filaments along thick filaments isolated from molluscan smooth muscle was observed. Along a single thick filament, actin filaments moved toward the center of the thick filament at the speed of 1.19 +/- 0.38 microns s-1 (mean +/- SD, n = 42) and detached themselves from it upon reaching the central zone. Movement of actin also occurred in the opposite direction, i.e., away from the center, albeit at a much lower velocity (0.09 +/- 0.07 microns s-1, n = 17). Thus, the thick filament shows functional bipolarity in terms of velocity but does not determine the direction of the movement.
Yamada
A
A
Zoological Institute, Faculty of Science, University of Tokyo.
Ishii
N
N
Takahashi
K
K
D008841:Actin Cytoskeleton / Q000648:ultrastructure; D000199:Actins / Q000502:physiology*; D000818:Animals; D008974:Mollusca; D009119:Muscle Contraction; D009130:Muscle, Smooth / Q000502:physiology*
D000199:Actins